Project Background

A number of Highways Agency road pavements have suffered inundation during flood events. Unless scouring occurs there is usually little visible evidence that the pavement has been waterlogged for a period of time.

Saturated unbound materials have less strength than in a dry condition. It is possible that the bound layers may also become weakened through a loss of support and degradation of the bound materials through hydraulic pressures and freeze/thaw conditions. It is not known whether the inundation episode gives rise to reduced life in the pavement through a weakening of the structure or whether the pavement recovers when water levels return to normal.

Project Background

ERA-NET ROAD initiated a transnational research project titled “Optimization of thin asphalt layers”. The DRI-BRRC-VTI Consortium was trusted with carrying out the project and began with a State-of-the-Art report covering, among other things, a literature study and an inventory of experience with using thin asphalt layers (TAL).

Project Objectives

To study wearing courses consists and gather detailed information on the use of thin layers and the experience obtained in Europe and elsewhere, if possible. The review of the literature to be supplemented by an inventory amongst distinguished specialists because the experi-ence of Project Consortium partners is...

Project Background

A major change in the surfacing materials being used on HA roads from HRA to thin surfacings has occurred over the last decade. These proprietary thin asphalt surfacing systems are permitted on trunk roads provided the system is approved under the Highway Authorities Product Approval Scheme (HAPAS). The full effects of this change are being assessed in terms of whole-life costs, sustainability and environmental impact and, in particular, estimates of their service life need to be made and validated. With this data, the methodology of whole-life costing can be properly extended to include the surfacing in addition to the pavement structure.

Project Objectives

Project Background

The Value Management (VM) process is used by HA for prioritising maintenance schemes on the network. Quite different approaches to VM are followed for Roads, Structures and LNMS schemes reflecting the fact that the VM processes have each evolved separately albeit with a common purpose of assessing need and prioritising maintenance spend. This does make comparing the relative benefits (i.e. value of undertaking the work) across the different strands potentially very difficult. Furthermore, risk is considered at various stages within each of these processes. However risk is dealt with differently across the different asset types and the overall consideration of risk is not fully understood by all those...

Project Background

The HA has a responsibility to ensure that its rock slope assets are safe and adequately managed. It is also necessary to monitor the slopes for signs of deterioration to allow for the efficient and economic maintenance of these assets. There is a need for the HA to implement a system for Rock Slope Hazard assessment to assist in fulfilling thee requirements.

Project Objectives

The objectives are to implement a system of Rock Slope Hazard Assessment that: Provides a consistent, appropriate & robust approach to initial risk assessment and identifies key actions; Ensures that subsequent condition surveys target features that may be subject to change over...

Project Background

Highways Agency have a number of ongoing research tasks at TRL where concrete specimens continue to be monitored. In addition there are several monitored field trials. There are also a number of large beams retained on site at TRL pending future research opportunities. These specimens were managed under two existing contracts which have now ended

Project Objectives

Periodic monitoring of specimens, and reporting on durability issues. Concrete deterioration is a relatively slow process and it is essential that data is collected over a long period to ensure that advice is sound. A small number of additional specimens in deteriorated condition will be...

Project Background

TRL has undertaken a number of projects for the Highways Agency to investigate the long term durability and the performance of a range of repair and rehabilitation techniques for concrete bridges. The research programme was aimed at reducing degradation of concrete bridges caused by de-icing and air bourne salts and freeze thaw action. Normally each of the projects lasted for 2-3 years and the work included manufacture of specimens for longer term weathering and exposure. The continued management and monitoring of these specimens formed the basis for a project to obtain information on longer-term performance. There are still several sets of specimens being stored at TRL including two large specimens to...

Project Background

It is the responsibility of the Highways Agency to ensure that structures on the Trunk Road and Motorway network in England are maintained in a safe and serviceable condition, and that the maintenance budget Is spent cost effectively, on the highest priority needs. It is also an objective that highway structures are constructed and maintained using materials and techniques to ensure that they maximise durability, minimise maintenance and are sustainable.

The Highways Agency also has higher level objectives such as 'Journey time reliability', 'Managing down costs', 'Speeding up delivery', as well as ensuring there is a safe and serviceable network, being a responsible owner, and managing...

Project Background

Managed Motorways (MM) is a tool-box of measures that facilitates the dynamic control of traffic for congestion and incident management; the tool-box' includes:
• Dynamic use of the Hard Shoulder
• Controlled Motorways
• Queue Protection
• Lane Specific Signalling
• Ramp Metering
The tools allow the road space to be managed in different ways for varying conditions to maximise capacity whilst providing a safe and informed environment for the travelling public and those working on, the network. This project is specifically concerned with the dynamic use of the hard shoulder (DHS).

Hard shoulders are generally in an unknown structural condition and...

Project Background

The Highways Agency is responsible for 2700km of motorway and 4350km of all purpose trunk roads worth £87 billion. Currently there are differences in the procedures used to design new pavements and those methods used to assess the potential future behaviour of in-service roads. These procedures are not robustly linked. The selection of common or related pavement responses that can be used for pavement design, measured during condition monitoring and then used in maintenance monitoring would unify the technical approaches to new and in-service roads. By establishing the measurements from condition monitoring equipment that are related to the selected pavement responses, new pavement design and structural...